package 

test;

import 

java.security.GeneralSecurityException;

import 

java.security.Key;

import 

javax.crypto.Cipher;

import 

javax.crypto.KeyGenerator;

import 

javax.crypto.SecretKey;

import 

javax.crypto.spec.SecretKeySpec;

public 

class 

AESCoder {

        

public 

static 

final 

String 

KEY_ALGORITHM

= 

"AES"

;

       

        

public 

static 

final 

String 

CIPHER_ALGORITHM

= 

"AES/EBC/PKCS5Padding"

;

       

        

//密钥算法

        

private 

static 

Key toKey(

byte

[] key){

              SecretKey secretkey = 

new 

SecretKeySpec(key,

KEY_ALGORITHM

);

               

return 

secretkey;

       }

       

        

public 

static 

byte

[] decrypt(

byte

[] data, 

byte

[] key) 

throws 

Exception, GeneralSecurityException{

              Key k= toKey(key);

              Cipher cipher=Cipher. getInstance(

CIPHER_ALGORITHM

);

              cipher.init(Cipher. 

DECRYPT_MODE

, k);

               

return 

cipher.doFinal(data);

       }

       

        

public 

static 

byte

[] encrytp(

byte

[] data, 

byte

[] key) 

throws 

Exception, GeneralSecurityException{

              

              Key k= toKey(key);

              

              Cipher cipher=Cipher. getInstance(

CIPHER_ALGORITHM

);

              

              cipher.init(Cipher. 

ENCRYPT_MODE

, k);

               

return 

cipher.doFinal(data);

       }

       

        

public 

static 

byte

[] initKey() 

throws 

Exception{

              KeyGenerator kg=KeyGenerator. getInstance(

KEY_ALGORITHM

);

              kg.init(256);

              SecretKey secretKey=kg.generateKey();

               

//获取密钥的二进制编码形式

               

return 

secretKey.getEncoded();

       }

}

对密钥规范的要求降低了，无需实现密钥规范类。